Control circuitry for a radio telephone

ABSTRACT

A control circuitry for a radio telephone having a transmitter, a receiver, a cradle and a handset. The handset includes a first computer having a stored program control therein, a first memory, a telephone number display and a pushbutton pad. The cradle includes a second computer having a stored program control therein, a second memory, a plurality of control switches and radio telephone status indicators. A dialed number is entered into the handset memory from the pushbutton pad, under control of the handset computer. Then during a telephone call, the entered number is transferred from the handset computer to the cradle computer and transmitted by the cradle computer. Frequently called numbers can be stored in the handset memory or the cradle memory and later, can be readily recalled and transmitted. The last dialed number can be automatically retransmitted in a subsequent call.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention relates to control circuitry for a radio telephone, andmore particularly, to stored program control for a radio telephone.

2. Description of the Prior Art

In the prior art, radio telephone control circuitry has been mechanizedwith discrete logic elements, resulting in a large number of circuitelements which physically occupy a large amount of space. This sizerestriction has dictated that the control circuitry must be located inthe cradle, not in the handset. A large number of logic elementscomplicates the control circuitry. The highly complex control circuitryis relatively expensive to build and maintain.

The control circuitry of the prior art is inflexible and not easilychanged or enhanced. In order to accommodate optional featuresadditional control circuitry must be added.

Prior radio telephones have primarily used the rotary dial to producethe dialed digits. The rotary dial introduces dial pulse distortion dueto the inherent inaccuracy of the dialing mechanism. This problem hasbeen partially overcome by utilizing dual tone dialing circuits.

The radio channel selection has previously been accomplished byindividual manually operated switches or by multiposition rotaryswitches. Expanded automatic and selective channel selection ispresently not available.

The foregoing deficiencies reveal a long felt need for a stored programcontrol circuitry for radio telephones that overcomes these limitations.

OBJECTS OF THE INVENTION

It is an object of the invention to provide an improved controlcircuitry for radio telephones that is inexpensive and compact.

It is a further object of the invention to provide a control circuitrythat is flexible with regard to the features that it provides, thatreconstructs and accurately forwards the dialed telephone number, andthat provides expanded automatic and specific radio channel selection bymeans of a circuitry incorporating stored program control.

It is a still further object of the invention to provide a controlcircuitry that has a relatively small number of circuit components,resulting in simplified maintenance and minimized power source currentdrain.

SUMMARY OF THE INVENTION

The present invention provides a control circuitry for a radio telephonehaving a transmitter, a receiver, a cradle, and a handset which hasmeans for dialing a telephone number consisting of a plurality ofdigits. The control circuitry comprises a first memory means and a firstcontrol means in the radio telephone handset and a second control meansin the radio telephone cradle. The first control means stores a dialednumber into the first memory means, reads out the stored dialed numberfrom the first memory means, converts the read out dialed number into apredetermined coded number, and sends the predetermined coded number tothe radio telephone cradle. The second control means receives thepredetermined coded number of from the first control means in thehandset and transmits the predetermined coded number.

According to a preferred aspect of the invention, for the first controlmeans, a first computer having a stored program therein is provided inthe radio telephone handset and, for the second control means, a secondcomputer having a stored program therein is provided in the radiotelephone cradle. According to another aspect of the invention, there isprovided, associated with the first computer, a first memory means and afirst indicating means and, associated with the second computer, asecond memory means and a second indicating means.

The first or handset computer stores the dialed number in the firstmemory means, reads out the stored dialed number from the first memorymeans, converts the read out dialed number into a predetermined codednumber, and sends the predetermined coded number to the cradle. Thehandset computer also enables the first indicating means to provide avisual indication of the dialed number.

The second or cradle computer receives the predetermined coded numberfrom the handset computer, stores the received predetermined codednumber in the second memory means, reads out the stored predeterminedcoded number from the second memory means, and transmits the read-outpredetermined coded number. In addition, the cradle computer enables thesecond indicating means to provide a visual indication of the radiotelephone status.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial view of the radio telephone handset and cradle.

FIG. 2 is a general block diagram showing the radio telephone handset,the radio telephone cradle, the junction box and the radio.

FIGS. 3A, 3B and 3C when arranged as shown in FIG. 3D show a detailedblock diagram of the radio telephone handset, the radio telephonecradle, the junction box and the radio.

FIGS. 4A and 4B in combination show a flow chart of the stored programcontrol for the radio telephone handset computer.

FIGS. 5A and 5B in combination show a flow chart of the stored programcontrol for the radio telephone cradle computer.

FIG. 6 is a timing diagram of the transfer of the dialed number from thehandset computer to the cradle computer and the outpulsing of the dialednumber from the cradle computer.

FIG. 7 is a block diagram of a typical computer for controlling thecradle or handset in accordance with the invention.

FIG. 8 is a table of the binary states placed on the C bus lines by thehandset computer in response to corresponding pushbuttons.

FIG. 9 is a table of the binary states placed on the C bus lines by thecradle computer in response to corresponding cradle control conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is shown a view of the radio telephone whichexemplifies the preferred embodiment of the invention. The radiotelephone consists of a handset 10 and a cradle 11 interconnected by acoil cord 14.

FIG. 2 is a general block diagram of the radio telephone showing thehandset 10, the cradle 11, the junction box 12, and the radio 13 and therespective interconnections between these components. The handset 10consists of a push button pad 21, a computer 20, a phone number display22, a speaker 25, and a microphone 24. The cradle consists of controlswitches 26, a computer 40, and channel and status displays 23. Thejunction box 12 interconnects the cradle 11 and the radio 13 and alsoprovides the power supply 27 for the cradle 11 and the handset 10. Theradio 13 sends control information to and receives control informationfrom the cradle computer 40, routes the microphone 24 to the radiotransmitter audio, and routes the receiver audio to the speaker 25. Theradio 13 contains the necessary tone generation and tone detectioncircuitry which, under the control of the cradle computer 20, producesthe appropriate tone signalling for a particular radio telephone system.The radio telephone is optimally suited to operate with the radiodescribed in Motorola, Inc., instruction manual entitled, "MotorolaPULSAR VHF Mobile Radiotelephone", published by Motorola EngineeringPublications, 1976, Chicago, Illinois.

FIGS. 3A, 3B and 3C when arranged as in FIG. 3D are a detailed blockdiagram of the exemplary embodiment of the invention. The handset 10 iscontrolled by a computer 20 having a stored program control therein. Forcomputer 20 any one of a number of computers packaged in an integratedcircuit made available recently by many manufacturers, such as theMotorola MC6801, may be used. This type of computer typically isarchitectured as illustrated in FIG. 7.

The handset computer 20 provides five strobe lines 35 to the 15 buttonsin the pushbutton pad 21. The pushbuttons include the numerical digits(0-9), the number pushbutton 130, the channel pushbutton 131, the memorypushbutton 132, the clear pushbutton 133 and the send pushbutton 134(see FIG. 1). The 15 buttons in the pushbutton pad 21 are organized in afive by three matrix. A button that is depressed routes the strobe line35 back to the computer 20 over the data lines 36 by way of the inputmultiplexer 31. A push-to-talk pushbutton 136 (FIG. 1) is present in thehandset 10 for manually activating the radio transmitter, the activationbeing shown by the transmit indicator 120 in FIG. 3B. The push-to-talkpushbutton 136 is electrically in parallel with the contacts of thenumber pushbutton 130.

The handset computer 20 enables each of the seven digits of the phonenumber display 22 by the seven digit control lines 37. When each digitis enabled by its respective digit control line 37, the predeterminedsegment for that digit of the display is selected by the seven segmentcontrol lines 38.

The handset computer 20 communicates to the cradle computer 40 by way ofthe four C bus lines 41. The handset computer 20 controls the directionof the data on the C bus lines 41 by means of the C bus control line 42.The handset computer 20 monitors the state of the C bus lines 41 by wayof the input multiplexer 31. The handset computer 20 loads data into thedata latch 30 which is then placed on the C bus lines 41 by activationof the C bus control line 42. Data on the C bus lines 41 is normallydirected from the cradle computer 40 toward the handset computer 20. Thehandset computer 20 alone dictates the state of the C bus control lines42.

The handset 10 contains a speaker 25 and a microphone 24 for voiceaudio. The voice audio from the microphone 24 is further amplified bythe microphone audio circuit 34.

The cradle computer 40 is a computer having a stored program therein,which is of similar architecture to the handset computer 20. The cradlecomputer 40 receives input data through the data routing multiplexer 46and the input multiplexer 47. Groups of four lines of data aremultiplexed onto the data routing bus 103 by the data routingmultiplexer 46. The various data lines being multiplexed are the C buslines 41, the D bus lines 102, the cradle pushbuttons 45 (store 143,delete 142, mode 140, party/auxiliary 141), and the off-hook pushbutton48 together with the supervisory unit lines, busy 104, supervisory key105, and search 106. The data routing bus 103 is then multiplexed by theinput multiplexer 47 onto the input multiplexer bus 110 together withthe four control lines, the hook switch line 50, the C bus control line42, the filtered ignition sense line 107, and the frame timer 108.

Data is routed from the cradle computer 40 on the seven data output line111. Four of the data output lines 111 are routed to the C bus datalatch 52, the supervisory unit data latch 55, and to the radio 13. Thefour data lines to the radio 13 are designated the A bus 112. The sevenoutput data lines 111 are also routed to the display drivers 56 tocontrol the segment selection of the channel display 57 and theselection of the status displays 58, the home indicator 150, the roamindicator 151, the manual indicator 152 and the busy indicator 153 (seeFIG. 1). The home, roam and manual indicators display the operationalmode of the radio telephone, as will be explained later. The busyindicator 154 is illuminated if the available radio channels in theparticular operational mode are busy. The data latch 52 places data ontothe C bus lines 41 under control of the C bus control line 42 from thehandset computer 20. The supervisory unit data latch 55 contains fourcontrol lines, the dial pulse line 83, the dial-off-normal/manualhookswitch line 84, the hookswitch/push-to-talk line 85 and 2805dial-off-normal line 86, which are routed to the supervisory unit 15 inthe radio 13. The digit control drivers 92 select the units or tensdigit of the channel display 57 or the status displays 58, each of whichis then illuminated in accordance with the data from the display drivers56. The display reset timer 93 suquentially enables each of the digitcontrol drivers 92 for 1.8 ms time periods. The dispay reset timer 93 isdriven by the 14 KHz clock 96 and reset by the cradle computer 40.

When the key switch 54 is activated, the battery A+ line 66 is connectedto the switched A+ line 68 which applies voltage to the handset displayregulator 53, the digit control drivers 92, the initializing circuit 94,the regulated power supply 27 in the junction box 12, and circuits inthe radio 13. The handset display regulator 53 is a series-passregulator which supplies 4.6 volts 123 to the handset phone numberdisplay 22. The initializing circuit 94 holds the handset computer 20and the cradle computer 40 in the reset mode until the key switch 54 isactivated. The initializing circuit 94 insures that both computers arein the proper start-up mode for radio telephone operation.

The receiver audio/ring line 113 from the radio supervisory unit 15routes receiver audio to the audio shaping circuit 101, the audio beingsuperimposed on a DC ring signal which is routed to the ring enablecircuit 100. When the radio supervisory unit 15 detects the tonesignalling for ringing, a DC voltage is placed on the receiveraudio/ring line 113 which is then detected by the ring enable circuit100. The ring enable circuit 100 activates the ring tone generatorcircuit 98 which gates an audio ring tone onto the receiver high line114 to the handset speaker 25. In the ring generator circuit 98, thealternating two tones, for example 1200 Hz and 875 Hz tones, composingthe ring signal, are created by dividing down the 7 KHz signal 125 fromthe divider circuit 95. When the handset 10 is removed to answer theincoming call, the ring tone generator circuit 98 is disabled andreceiver audio is routed to the handset speaker 25 through the aduioshaping circuit 101.

The 14 KHz clock 96 feeds the divider circuit 95 which develops the 7KHz signal 125 for the ring tone generator circuit 98, the frame timer108 and the 1200 Hz signal 126 for the busy tone generator circuit 97.The busy tone generator circuit 97 is activated by the busy line 104from the radio supervisory unit 15. When enabled, the busy tonegenerator circuit 97 gates a busy tone onto the receive audio/ring line113. In the busy tone generator circuit 97, the busy tone (400 Hz) iscreated by dividing down the 1200 Hz signal from the divider circuit 95and interrupting it at a 1.7 Hz rate.

The transmit indicator 120 is enabled by the supervisory key line 105 orthe push-to-talk output line 121 from the cradle computer 40, beingilluminated whenever the radio transmitter is on.

The junction box 12 is the distribution point for interconnections withthe cradle 11 via the ribbon cable 64, the radio 13 via the controlcable 65, the battery A+ line 66, and the ignition sense line 60 fromthe vehicle ignition switch. The ignition sense line 60 is routed to theignition sense filter 67 which removes voltage transients which occur onthe ignition sense line 60. The filtered ignition sense line 107 is theoutput of the ignition sense filter 67 and is routed to the cradle inputmultiplexer 47 and the regulated power supply 27.

The regulated power supply 27 has at its input the battery A+ line anddelivers the regulated voltage 62 to the control circuits in the cradle11 and handset 10. The regulated power supply 27 contains circuitry toprotect against over voltage or short circuits on the regulated voltage62. If the filtered ignition sense line 107 or the switch A+ line 68 isactivated, the regulated power supply 27 delivers +15 volts to thecircuitry in the cradle 11 and handset 10. If neither of theseconditions is present, the regulated power supply 27 delivers a minimumof +11.6 volts.

The radio 13 contains the cradle interface board 75, a frequencysynthesizer 16, a radio frequency transmitter, a radio frequencyreceiver, and a supervisory unit 15. The interface board 75 contains thediode matrix 70, the manual/automatic latch 71, the channel data latch72, and the search control latch 73. Data is transferred from the cradlecomputer 40 to the latches on the interface board 75 by means of the Abus lines 112. The manual/automatic line 80 from the manual/automaticlatch 71 is routed to the supervisory unit 15. The channel select lines81 from the channel data latch 72 are routed to the frequencysynthesizer 16 for selecting the transmitter and receiver frequencies.The search control latch 73 enables or disables the search controlswitch 74 which gates the scan enable line 82 from the supervisory unit15 to the search line 106.

The diode matrix 70 is organized into a 10 × 4 array of 40 diodes whichis capable of storing 40 bits of binary data. Diodes are selectivelyremoved to encode a particular set of data. The presence of a diode is abinary one state, and the absence of a diode a binary zero state. Thediode matrix 70 stores the home radio channel list, program constantssuch as the total number of radio channels, and program functions suchas fast channel scanning. The diode matrix 70 is addressed by the A buslines 112 from the cradle computer 40. The A bus lines 112 are decodedinto one of 10 columns select lines which accesses four diodes. The Dbus lines 102 are the row output lines from the four diodes in aselected column. When a column of four diodes is selected by the A buslines 112, the presence or absence of each of these four diodes can bedetermined from the D bus lines 102.

The supervisory unit 15 in the radio 13 generates and detects the tonesignalling for a particular radio telephone system. The supervisory unitis under control of the cradle computer 40. The cradle computer 40receives the busy line 104 and the supervisory key line 105 from thesupervisory unit 15 and routes to the supervisory unit 15 the dial pulseline 83, the dial-off-normal/manual hookswitch line 84, thehookswitch/push-to-talk line 85, and the 2805 dial-off-normal line 86.The supervisory unit 15 controls the receiver audio/ring line 113 whichis routed to the audio circuits in the cradle 11. The microphone highline 115 from the handset microphone audio circuit 34 is routed to thesupervisory unit 15 and other radio circuits.

The radio telephone embodying the present invention can operate in manydifferent mobile telephone systems. The preferred embodiment of theradio telephone can accommodate radio telephone systems having manual orautomatic radio channel selection, manual or automatic transmittercontrol and operator assisted or automatic direct dialing. The radiotelephone has three modes of operation, home, roam, and manual. The homemode is an automatic mode of operation using a set of home radiochannels for a local geographic area. The roam mode is also an automaticmode of operation, but a set of predetermined foreign radio channels areused for a geographic area outside the home area. The manual mode is formanual operation in manual radio telephone systems.

Automatic operation of the radio telephone will best demonstrate thepreferred aspects of the invention. Placing a call from the radiotelephone is essentially the same in the home and roam modes, thedifference being the set of radio channels used. First, the desiredtelephone number is entered from the pushbutton pad 21. Telephonenumbers with seven digits or less can be entirely displayed in the phonenumber display 22. Next, the handset 10 is released from the cradle 11activating the hookswitch 50. Alternatively, the off-hook pushbutton 48can be depressed to initiate the call without removing the handset 10from the cradle 11.

The radio telephone automatically scans the available channels. If anavailable channel is found, the green transmit indicator 120 will comeon. If all of the channels are busy, the red busy indicator 153 willcome on and the busy tone generator 97 will be enabled providing anaudible busy tone to the handset speaker 25.

Once dial tone is received over an available channel, the sendpushbutton 134 on the pushbutton pad 21 is depressed to transmit thedialed number. The dialed number is transferred by the handset computer20 to the cradle computer 40 and outpulsed by the cradle computer 40 asshown in FIG. 6.

FIG. 6 illustrates the transfer and outpulsing of an entered telephonenumber, the number being the directory assistance number, 411. Once thehandset send pushbutton 134 has been depressed 601, the C bus controlline 42 changes state to direct data from the handset computer 20 to thecradle computer 40 over the C bus lines 41. The handset computer 20places binary control data 602 on the C bus lines to indicate to thecradle computer 40 that a dialed number will be transferred. Next, thebinary coding of the digit 4 (603) is placed on the C bus lines 41 bythe handset computer 20. The cradle computer 40 receives the binarycontrol data 602 and digit 4 (603) on the C bus lines 41 and activatesthe dial-off-normal line 84 while the digit 4 (603) is outpulsed on thedial pulse line 83. After the digit 4 (603) has been outpulsed on thedial pulse line 83, the cradle computer 40 places a binary acknowledge604 on the C bus lines 41 and deactivates the dial-off-normal line 84.When the binary acknowledge 604 is detected by the handset computer 20,the C bus control line 42 is activated and the binary digit 1 (605) isplaced on the C bus lines 41 and the process is repeated. Successivedigits are transferred in a similar manner until all digits have beenoutpulsed.

When the call is completed, conversation can take place. At the end ofthe call, the handset 10 is placed back into the cradle 11.

As illustrated in FIG. 6, the binary codes on the C bus lines 41together with the C bus control line 42 are used to communicateinformation between the handset computer 20 and the cradle computer 40and vice versa. The C bus lines 41 provide for up to 16 differentstates. As can be ascertained from FIG. 6, the decimal digit "4" (603)is encoded as a binary four "0100", decimal digit "1" (605) a binary one"0001". Also, whenever data is placed on the C bus lines 41 by thehandset computer 20, the handset computer 20 also places a logical oneon the C bus control line 42 to alert the cradle computer 40 that datawill follow.

The coding of the C bus lines 41 which correspond to each pushbutton ofthe handset are summarized in FIG. 8. Having sixteen available states ofthe C bus lines 41, any suitable assignment of states can be made forthe pushbuttons. However, for the numerical pushbuttons "1 thru 0", itis convenient to assign the corresponding binary states which areequivalent to the number of dial pulses for the particular pushbutton.For example, pushbutton "O" has been assigned binary state "1010" sincepushbutton "O" is representative of ten dial pulses. Once havingassigned the binary states for the numercial pushbuttons, the remainingbinary states of the C bus lines 41 can be assigned to the remainingpushbuttons in any suitable manner. Since the number pushbutton 130 andthe push-to-talk pushbutton 136 are electrically in parallel, they havethe same binary state "1011".

A similar table in FIG. 9 illustrates the binary codes placed on the Cbus control lines 41 which correspond to cradle control conditions.During the dialing operation show in FIG. 6, the C bus lines 41 have thestate "0100" indicating the off-hook condition when the C bus control 42is a logical zero. Also, the binary state "0110" is placed on the C buslines 41 by the cradle computer 40 to acknowledge (604) the completionof outpulsing of each digit of a telephone number.

In response to the store pushbutton 143, the binary state "0001" isplaced on the C bus lines 41 by the cradle computer 40. The binary state"0011" for the standby condition is placed on the C bus lines by thecradle computer 40 when the keyswitch 54 is on and the ignition sense 60indicates that the automobile ignition is off. Again, there are sixteenavailable binary states for cradle control conditions, of which onlyfive binary states have been assigned as indicated in FIG. 9.

The transfer and outpulsing of an entered telephone number shown by thetiming diagram of FIG. 6 illustrates the binary states of FIGS. 8 and 9.FIG. 6 further shows that the handset control 602 includes both the sendbinary code "1110" and the number binary code "1011". However, thenumber binary code is essentially superfluous, only being included toactivate auxiliary control functions to the supervisory unit 13, such asthe DON/MAN MKS line 84, and is not essential in practicing the presentinvention.

An in-coming call is detected by the supervisory unit 15 which places aDC ring signal on a receiver audio/ring line 113. The DC ring signal isdetected by the ring enable circuit 100 which then activates the ringtone generator circuit 98. The ring signal is gated to the handsetspeaker 25 and audibly alerts one of the in-coming call. The ring signalis removed when the handset 10 is removed from the cradle 11 to answerthe call. The green transmit indicator 120 is illuminated when thehandset 10 is picked up, and conversation can take place. When the callis completed, the handset 10 then is placed back into the cradle 11.

Many other features are made available by the flexibility of the storedprogram control. Ten different telephone numbers can be stored for laterrecall, two with up to 16 digits being stored in the memory of thehandset computer 20 and eight with up to 11 digits stored in the memoryof the cradle computer 40. The stored telephone numbers are recalled bydepressing the memory pushbutton 132 and then the numerical digit whichcorresponds to the desired telephone number. The stored number istransferred to the handset 10 and loaded into the phone number display22, and is transmitted when the second pushbutton 134 is depressed afterreceiving dial tone. The last number dialed can be retransmitted bydepressing the send pushbutton 134 after receiving dial tone.

When on-hook, a telephone number with more than seven digits can bereviewed by repeatedly depressing the number pushbutton 130 to step thetelephone number across the phone number display 22. If a telephonenumber has been incorrectly entered, the number can be cancelled bydepressing the clear pushbutton 133. Repeatedly depressing the channelpushbutton 131 will sequentially load the channel display 57 with theradio channels from the home list if in the home mode or from the roamlist if in the roam mode.

Telephone numbers preceeded by special access codes (such as a 9) whichroute the caller to an access dial tone can be entered from thepushbutton pad 21. While on-hook, the access code is entered first.Then, the send pushbutton 134 is depressed causing a pause code to bestored and a dash to be loaded into the phone number display. Finally,the telephone number is entered. The access code, dash, and telephonenumber together can total up to 16 digits like any other enteredtelephone number. When dial tone is received during the ensuingtelephone call, depressing the send pushbutton 134 causes the accesscode to be transmitted. When the access dial tone is received,depressing the send pushbutton 134 again causes the telephone number tobe transmitted. Additional pause codes can be entered in a telephonenumber if desired. Telephone numbers with pause codes can also bestored.

Depressing the mode pushbutton 140 in the cradle 11 steps the radiotelephone between the home, roam and manual mode of operation. The storepushbutton 143 is used to store telephone numbers and to store radiochannel numbers in the roam list. The delete pushbutton 142 is used todelete radio channels from the roam list. The auxiliary alert/partypushbutton 141 will produce an auxiliary output 161 from the auxiliarydriver 160 upon receipt of an incoming call if depressed when thehandset 10 is on-hook and will activate the revertive call mode ifdepressed when the handset 10 is off-hook.

Special program functions and program constants, such as the lowestchannel number, can be selectively included or deleted by the presenceor absence of diodes in the diode matrix 70. The list of available homeradio channels is also programmed in the diode matrix 70.

The stored program control for the handset computer 20 can be generallyunderstood by referring to the flow chart of FIGS. 4A and 4B. Threebasic functions are performed by the handset stored program control; (1)scan the pushbutton pad 21 for depressed pushbuttons, (2) generate datafor the digit control lines 37 and segment control lines 38 to properlyilluminate the phone number display 22 and (3) communicate with thecradle computer 40 over the C bus lines 41.

Referring to the flow chart of FIG. 4A and 4B, the handset storedprogram control begins at the step of program initialization, this stepbeing represented by box 401. During initialization the program pointersand control status locations are up-dated in preparation for subsequentprogram operations. The program then proceeds to box 402 where the phonenumber display 22 is refreshed. Next, the state of the pushbuttons inthe pushbutton pad 21 and the state of the C bus lines 41 are inputtedand stored as shown in box 403. The data received is then compared tothe previous data in order to debounce changes in the data. New data isaccepted if the last two samples are in agreement. If new data has notbeen found, the test represented by decision box 404, the NO branch 405is followed back to box 402 to continue to look for new data. Otherwise,the YES branch 406 is followed and the new data is decoded as indicatedby box 407. The program now branches along path 408 to the next boxdepending on which operation is commanded by the decoded data.

The program proceeds along path 408 to box 412 if the clear pushbutton133 has been decoded. Proceeding to box 413, the clear operation cancelsthe telephone number that was entered, blanks the phone number display22 and terminates any operation that is underway. Next, the programreturns along path 409 to box 402 to resume searching for new data.

If a digit (0-9) of a telephone number entered from the pushbutton pad21 has been decoded, the program proceeds along path 408 to box 410. Thedigit of the telephone number is stored in the last-number-called memorylocation and loaded into the phone number display 22 as shown in box411. The program then returns along path 409 to box 402 to resumesearching for new data.

If the number pushbutton 130 has been decoded, the program proceedsalong path 408 to box 414. The phone number display 22 is then blankedas shown in box 415. Next, the previously entered telephone number,consisting of up to 16 digits, is shifted into the phone number display22 a digit at a time as the number pushbutton 130 is repeatedlydepressed, this step being represented by box 416. The program thenreturns along path 417 to box 401.

If the send pushbutton has been decoded, the program proceeds along path408 to box 420. First, the phone number display 22 is blanked as shownin box 421. Next, the previously entered telephone number is transferredby the handset computer 20 to the cradle computer 40 over the C buslines 41. As the telephone number is transferred, each digit issequentially loaded into the phone number display 22, these steps beingrepresented by box 422. The handset computer 20 transfers a digit andthen waits for the cradle acknowledge. If the cradle acknowledge is notreceived, the test being represented by decision box 423, the NO branch424 is taken and the wait is continued. Otherwise, the YES branch 425 istaken and a test is made to determine whether the last digit of thetelephone number has been sent, as indicated by decision box 426. If thelast digit has not been sent, the NO branch 427 is taken to box 422 andanother digit is transferred. Otherwise, the YES branch 428 is taken toreturn along path 417 to box 401.

If the memory pushbutton 132 has been decoded, the program proceedsalong path 408 to box 430. Next, a numerical digit which is entered fromthe pushbutton pad 21 is used to select the stored telephone number,this step being represented by box 431. Proceeding to box 432, theselected telephone number is retrieved from its respective memorylocation and loaded into the last-number-called memory location and intothe phone number display 22. The telephone number accessed is now readyto be transmitted during an ensuing call. The program then returns alongpath 417 to box 401.

If the store command from the cradle 11 has been decoded, the programproceeds along path 408 to box 433. If the entered number has one or twodigits, the test represented by decision box 434, the YES branch 435 istaken, and the entered number is treated as a channel number. Next, thechannel number entered is transferred by the handset computer 20 to thecradle computer 40 and stored in the cradle memory, this step beingrepresented by box 441. When all of the radio channels have been loadedinto the roam list, the channel pushbutton 131 can be depressed toreview the list of radio channels. The program then returns along path417 to box 401. If the entered number has more than two digits, the NOpath 436 is taken. The next numerical digit that is entered from thepushbutton pad 21 determines the memory location into which thepreviously entered telephone number is to be stored, as represented bybox 442. The telephone number is transferred by the handset computer 20to the designated memory location when the store pushbutton 143 isdepressed, as indicated by box 443. The program then returns along path417 to box 401.

If the channel pushbutton 131 is decoded, the program proceeds alongpath 408 to box 444. Next, the channel command from the handset computer20 is sent to the cradle computer 40 causing the next available radiochannel number to be loaded into the channel display 57, as representedby box 445. The program then returns along path 417 to box 401.

The stored program control for the cradle computer 40 can be generallyunderstood by referring to the flow chart of FIGS. 5A and 5B. The cradlestored program control performs the following basic functions: (1) scanthe cradle pushbuttons 45, off-hook pushbutton 48 and hookswitch 50; (2)illuminate the channel display 57, the status displays 58 and thetransmit indicator 120; (3) communicate with the radio supervisory unit15; (4) control the radio channel frequency; (5) access information fromthe diode matrix 70; and (6) communicate with the handset computer 20over the C bus data lines 41. The cradle program is divided into fiveframes during which specific data is transmitted, received and reviewed,each frame being completed is slightly less than 2.3 milliseconds.During the remaining time of each frame, the program up-dates controlstatus, monitors critical inputs, and transmits dialing.

Referring to FIGS. 5A and 5B, the program begins at the step of programinitialization where the program pointers and program control statuslocations are up-dated in preparation for subsequent program operations,as represented by box 501. Next, the off-hook pushbutton 48, thehookswitch 50 and the filtered ignition sense 107 are sampled todetermine if any change has occurred, as represented by box 502. Thesampled state of the signal is compared to the previous state of thesignal in order to debounce the signals. A change in state is acceptedif the present and previous states reflect the changed state. Then,radio telephone control status is up-dated in accordance with the newdata, as indicated by box 503.

Next, at decision box 504 the 2.3 millisecond frame timer 108 is testedfor a change of state. If the frame timer 108 has not changed state, theNO branch 505 is taken to return along path 507 to box 501. Otherwise,the YES branch 506 is taken to the decision box 510. If the radiotelephone is in the dialing mode, the YES branch 511 is taken to box513. The digits of the dialed number are transmitted to theradioupervisory unit 15 over the dial pulse line 83. The make-breakratio of the dialed digits on the dial pulse line 83 is accuratelycontrolled by the cradle computer 40. Otherwise, the NO branch 512 istaken to box 514. Next, the frame counter is incremented and the programadvances to the next sequential frame along path 508.

If the frame counter is in state 1, the program advances along path 508to frame 1 as shown in box 523. Next, the digit control driver 92 forthe cradle status displays 58 is enabled to illuminate the statusdisplays 58 in accordance with the data from the display drivers 56,this step being represented by box 524. Proceeding to box 525, data fromthe handset computer 20 is sampled on the C bus lines 41. The handsetdata is debounced and stored for subsequent updating of the radiotelephone control status. Next, the supervisory unit busy line 104 istested in the decision box 530. If the busy line 104 is activated, theYES branch 531 is taken to box 522 where the busy indicator 153 isilluminated. Otherwise the NO branch 532 is taken to the decision box534. If the handset push-to-talk pushbutton 136 has been activated, theYES branch 535 is taken to box 537 where the radio transmitter indicator120 is illuminated. Otherwise, branch 536 is taken to return along path507 to box 501.

If the frame counter is in state 2, the path 508 is taken to frame 2 asshown in box 520. Next, the digit control driver 92 for the tens digitof the channel display 57 is enabled to illuminate the tens digit inaccordance with the data from the display drivers 56, this step beingrepresented by box 521. Proceeding to box 522, supervisory unit datalines are sampled by the cradle computer 40. The supervisory unit datais debounced and stored by the cradle computer 40 for subsequentup-dating of the radio telephone control status. The program thenproceeds to decision box 530 as described previously for frame 1.

If the frame counter is in state 3, path 508 is taken to frame 3 asshown in box 515. Proceeding to box 516, the digit control driver 92 forthe units digit of the channel display 57 is enabled to illuminate theunits digit in accordance with the data from th display drivers 56.Next, the cradle pushbuttons 45 are sampled by the cradle computer 40 asindicated by box 517. The data representing the states of the cradlepushbuttons 45 is debounced and stored by the cradle computer 40 forsubsequent up-dating of the radio telephone control status. The programthen proceeds to dicision box 530 as described previously for frame 1.

If the frame counter is in state 4, path 508 is taken to frame 4 asshown in box 550. Proceeding to decision box 551, if the radio telephoneis in the search mode, the YES branch 552 is taken to box 554 where thenext available radio channel is accessed. Otherwise, the NO branch 553is taken to box 555. The cradle computer 40 then transfers the currentradio channel number to the data latch 72 via the A bus lines 112. Thechannel select data lines 81 from the data latch 72 are routed to thefrequency synthesizer 16 to determine the radio channel frequency. Next,the maximum radio channel number is addressed in the diode matrix 70 bythe A bus lines 112 and read into the cradle computer 40 via the D buslines 102, as represented by box 556. The program then returns alongpath 507 to box 501.

If the frame counter is in state 5, path 508 is taken to frame 5 asshown in box 540. Next, the frame counter is reset to frame zero asshown in box 541. Proceeding to the decision box 542, if the radiotelephone is in the search mode, the YES branch 543 is taken to box 554where the next available radio channel is accessed. Otherwise, the NObranch 544 is taken to box 545. The cradle computer 40 loads the datalatch 52 with current data to be transferred to the handset computer 20on the C but lines 41 and loads data latch 55 with the current states ofthe supervisory unit control signals. The program then returns alongpath 507 to box 501.

The foregoing embodiments have been intended as illustrations of theprinciples of the present invention. Accordingly, other embodiments canbe devised by those skilled in the art without departing from the spiritand scope of the principles of the present invention. For example, thefirst control means and second control means can be consolidated into asingle control means. Such a consolidated control means and a memorymeans can be located in either the handset 10, the cradle 11, or theradio 13. Likewise the first memory means associated with the firstcontrol means can be located in the cradle associated with the secondcontrol means. The illustrative embodiment of the invention shows acomputer 20 in the handset 10 and a computer 40 in the cradle 11. Thememory means for storing the dialed numbers can be included in eitherthe handset computer 20 or the cradle computer 40. The functions ofthese two computers can be consolidated into one computer which issituated in either the handset 10, the cradle 11, or the radio 13.

I claim:
 1. A control circuitry for a radio telephone transceiverincluding a transmitter, a receiver, a supervisory unit for providingsupervisory signalling between the radio telephone transceiver and abase station, a cradle, and a handset having a pushbutton dial forentering the digits of a telephone number, said control circuitrycomprising:a first computer having a first read-only memory for storinga first control program and a first read-write memory, said firstcomputer being disposed in the handset, said first computer receivingthe entered telephone number, converting the received telephone numberto a related coded telephone number and storing the related codedtelephone number in the first read-write memory; a second computerhaving a second read-only memory for storing a second control program,and a second read-write memory, said second computer being disposed inthe cradle; a bidirectional data bus having a plurality of data linesfor coupling said first computer to said second computer; a data-buscontrol line from said first computer for controlling the direction ofdata carried on said bidirectional data bus; and a second pushbuttonlocated on the pushbutton dial, said first computer responsive to anactivation of said send pushbutton for reading out from the firstread-write memory the stored related coded telephone number, providing apredetermined first binary state on said data-bus control line fordirecting data from said first computer to said second computer, andcoupling in succession the digits of the read-out related codedtelephone number to said bidirectional data bus, said second computerresponsive to the predetermined first binary state on said data-buscontrol line for successively receiving the digits of the related codedtelephone number from said bidirectional data bus and outpulsing thereceived digits of the related coded telephone number to the supervisoryunit.
 2. The control circuitry according to claim 1, wherein the handsetincludes a first indicating means, said first computer enabling thefirst indicating means to provide visual indication of the digits of theentered telephone number.
 3. The control circuitry according to claim 2,wherein said first indicating means provides for the display of up toseven digits of an entered telephone number.
 4. The control circuitryaccording to claim 2, wherein said cradle includes a second indicatingmeans, said second computer enabling said second indicating means toprovide visual indication of a predetermined status of said radiotelephone transceiver.
 5. The control circuitry according to claim 1,wherein the second read-only memory includes a matrix of diodes forstoring predetermined data, said second computer interrogating the diodematrix for the presence or absence of diodes to access the predetermineddata.
 6. The control circuitry according to claim 1, wherein said cradleincludes an off-hook switch for enabling said transmitter withoutremoving said handset from said cradle.
 7. The control circuitryaccording to claim 6, wherein the pushbutton dial is spatially disposedon the handset to enable the entering of a telephone number withoutremoving the handset from the cradle.
 8. The control circuitry accordingto claim 1, wherein the second conrol program of said second computerincludes means for providing home operation of said radio telephone. 9.The control circuitry according to claim 8, wherein the second controlprogram includes means for selecting a non-busy home radio channel froma plurality of predetermined home radio channels.
 10. The controlcircuitry according to claim 1, wherein the second control program ofsaid second computer includes means for providing roam operation of saidradio telephone.
 11. The control circuitry according to claim 10,wherein the second control program includes means for selecting anon-busy roam radio channel from a plurality of predetermined roam radiochannels.
 12. The control circuitry according to claim 1, wherein thesecond control program of said second computer includes means forproviding manual operation of said radio telephone.
 13. The controlcircuitry accrording to claim 1 wherein said plurality of second controlswitches includes a mode switch, said second computer stepping betweenhome, roam and manual operational modes in response to each activationof the mode switch.
 14. A control circuitry for a radio telephonetransceiver including a transmitter, a receiver, a supervisory unit forproviding supervisory signalling between the radio telephone transceiverand a base station, a cradle, and a handset having a pushbutton dial forentering the digits of a telephone number, said control circuitrycomprising:a first computer having a first read-only memory for storinga first control program and a first read-write memory, said firstcomputer being disposed in the handset, said first computer receivingthe entered telephone number, converting the received telephone numberto a related coded telephone number and storing the rlated codedtelephone number in the first read-write memory; a second computerhaving a second read-only memory for storing a second control program,and a second read-write memory, said second computer being disposed inthe cradle; a bidirectional data bus having a plurality of data linesfor coupling said first computer to said second computer; a data-buscontrol line from said first computer for controlling the direction ofdata carried on said bidirectional data bus; a plurality of firstcontrol switches disposed in the handset; a plurality of second controlswitches disposed in the cradle; said first computer responsive to anactivation of each respective first control switch for providing apredetermined first binary state on said data-but control line fordirecting data from said first computer to said second computer andcoupling a related binary first control code for the respective firstcontrol switch to said bidirectional data bus, said second computerresponsive to the predetermined first binary state on said data-buscontrol line and the related binary control code on said bidirectionaldata bus for providing a corresponding control signal to the supervisoryunit; and said second computer responsive to an activation of eachrespective second switch for coupling a related binary second controlcode to said bidirectional data bus in the absence of the predeterminedfirst binary control state on said data-bus control line, said firstcomputer responsive to the related binary second control code forstoring the status of the corresponding respective second switch. 15.The control circuitry according to claim 14, wherein said plurality offirst control switches includes a clear switch, said first computerclearing the stored related coded telephone number from the firstread-write memory in response to an activation of the clear switch. 16.The control circuitry according to claim 14, wherein said handsetfurther includes a first indicating means, said first computer enablingthe first indicating means to provide visual indication of the digits ofthe entered telephone number.
 17. The control circuitry according toclaim 16, wherein said plurality of first control control switchesincludes a number switch, said first computer first blanking the firstindicating means and subsequently shifting the digits of the enteredtelephone number into the first indicating means one digit at a time inresponse to the first and subsequent activations, respectively, of thenumber switch.
 18. The control circuitry according to claim 14, whereinsaid plurality of second control switches includes a key switch, saidfirst computer and said second computer being held reset in a standbymode until said key switch is activated.
 19. The control circuitryaccording to claim 14, wherein said plurality of first control switchesincludes a send switch; said first computer responsive to an activationof the send switch for providing the predetermined first binary state onsaid data-bus control line, coupling first the related binary firstcontrol code for the send switch to said bidirectional data bus, readingout from the first read-write memory the stored related coded telephonenumber, and coupling in succession the digits of the read-out relatedcoded telephone number to said bidirectional data bus; and said secondcomputer responsive to the predetermined first binary state on saiddata-bus control line and the related binary first control code for thesend switch on said bidirectional data bus for successively receivingthe digits of the related coded telephone number from said bidirectionaldata bus and successively outpulsing the received digits of the relatedcoded telephone number to the supervisory unit.
 20. The controlcircuitry according to claim 19, wherein said first computer isresponsive to subsequent activations of the send switch.
 21. The controlcircuitry according to claim 14, wherein said plurality of secondcontrol switches includes a store switch, in response to an activationof the store switch said first computer providing the predeterminedfirst binary state on said data-bus control line, reading out from thefirst read-write memory the stored related coded telephone number, andcoupling in succession the digits of the readout related coded telephonenumber to said bidirectional data bus; and said second computersuccessively receiving the digits of the related coded telephone numberfrom said bidirectional data bus and storing the received digits of therelated coded telephone number in the second read-only memory.
 22. Thecontrol circuitry according to claim 21, wherein said plurality of firstcontrol switches includes a memory switch, in response to an activationof the memory switch said second computer reading out from the secondread-write memory the stored related coded telephone number, andcoupling in succession the digits of the read-out related codedtelephone number to said bidirectional data bus; and said first computersuccessively receiving the digits of the related coded telephone numberand storing the received digits of the related coded telephone number inthe first read-only memory.
 23. The control circuitry according to claim21, wherein channel numbers are entered as telephone numbers having atmost two digits, said second computer converting received related codedtelephone numbers having at most two digits to related coded channelnumbers and storing the related coded channel numbers in the secondread-write memory.
 24. The control circuitry according to claim 23,wherein said plurality of second control switches includes a deleteswitch, said second computer deleting all stored related coded channelnumbers from the second read-write memory in response to an activationof the delete switch.
 25. The control circuitry according to claim 14,wherein said plurality of second control switches includes a hookswitch,said second computer selecting a non-busy channel from a plurality ofpredetermined radio channels stored in the second read-write memory inresponse to activation of the hookswitch when the handset is removedfrom the cradle.
 26. The control circuitry according to claim 25,wherein the cradle further includes an indicating means, said computerenabling the second indicating means to provide visual indication of theselected radio channel.
 27. The control circuitry according to claim 26,wherein said plurality of first control switches includes a channelswitch, in response to each activation of the channel switch saidcomputer enabling the second indicating means to provide visualindication of successive ones of the predetermined radio channels.
 28. Acontrol circuitry for a radio telephone transceiver including atransmitter, a receiver, a supervisory unit for providing supervisorysignalling between the radio telephone transceiver and a base station, acradle and a handset having a pushbutton dial for entering the digits ofa telephone number, said control circuitry comprising:a first displaydisposed in the handset for displaying the digits of the enteredtelephone number; a first microcomputer having a first read-only memoryfor storing a first control program and a first read-write memory, saidfirst microcomputer being disposed in the handset; said firstmicrocomputer receiving the entered telephone number, enabling the firstdisplay to display the digits of the received telephone number,converting the received telephone number to a related coded telephonenumber and storing the related coded telephone number in the firstread-write memory; a second microcomputer having a second read-onlymemory for storing a second control program, and a second read-writememory, said second microcomputer being disposed in the cradle; abidirectional data bus having a plurality of data lines for couplingsaid first microcomputer to said second mircocomputer; a data-buscontrol line from said first microcomputer for controlling the directionof data carried on said bidirectional data bus; and a plurality of firstcontrol pushbuttons disposed in the handset, said plurality of firstcontrol pushbuttons including a send pushbutton, said firstmicrocomputer responsive to an activation of said send pushbutton forreading out from the first read-write memory the stored related codedtelephone number, providing a predetermined first binary state on saiddata-bus control line for directing data from said first microcomputerto said second microcomputer, initially coupling a related binary firstcontrol code for the send pushbutton to said bidirectional data bus andthereafter coupling in succession the digits of the read-out relatedcoded telephone number to said bidirectional data bus, said secondmicrocomputer responsive to the predetermined first binary state on saiddata-bus control line and the related binary first control code for thesend pushbutton on said bidirectional data bus for successivelyreceiving the digits of the related coded telephone number from saidbidirectional data bus and outpulsing the received digits of the relatedcoded telephone number to the supervisory unit; a plurality of secondcontrol pushbuttons disposed in the cradle, said second microcomputerresponsive to an activation of reach respective second pushbutton forcoupling a related binary second control code to said bidirectional databus in the absence of the predetermined first binary control state onsaid data-bus control line, said first microcomputer responsive to therelated binary second control code for storing the status of thecorresponding respective second pushbutton.
 29. The control circuitryaccording to claim 28, wherein said second microcomputer includes asecond read-only memory for storing a list of predetermined radiotelephone channels, program constants and program functions.
 30. Thecontrol circuitry according to claim 29, wherein the second read-onlymemory includes a matrix of diodes, said second microcomputerinterrogating the diode matrix for the presence of selected diodes toaccess corresponding predetermined radio telephone channels, programconstants and program functions.